Rennlist

Failing O2 sensor?

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3 captured repliesDiscussion pagination complete · Source accounts, not a confirmed diagnosis

THIS DISCUSSION / SOURCE-DERIVED OVERVIEW

Discussion summary

YOUR RESEARCHFailing O2 sensor?

Leading reported evidence

Replace oxygen sensors

Performed · outcome unconfirmed

No successful repair reported for this finding.

0
Reported fixes: 0
Unsuccessful attempts: 1
Discussions

Read evidence and context

Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.

Discussions that performed work without a confirmed outcome: 1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Performed · outcome unconfirmed · Original poster
The O2 sensors were replaced about 2 years ago.
Original post Read captured discussion
Failing O2 sensor?

Frequently discussed work

Replace much, if any

No successful repair reported for this finding.

0
Reported fixes: 0
Unsuccessful attempts: 1
Discussions

Read evidence and context

Discussions that contain suggestions: 1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Suggestion · Original poster
I don�t think my driving habits have changed much, if any.
Original post Read captured discussion
Failing O2 sensor?

Read full discussion summary

Leading evidence: 'Replace oxygen sensors' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Replace much, if any' (1 discussions). For that action, 0 discussions report a resolution and 0 report an unsuccessful attempt. No action has an explicit, attributable resolution report under the current rules. These are forum reports and suggestions, not a confirmed diagnosis.

Source reports, not a diagnosis or a success probability. Counts refer to discussions and can overlap.

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1 matching discussions · 3 captured posts examined · 0 partial discussions

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Replace much, if any

Suggestion or failed attempt

No successful repair reported for this finding.

0
Reported fixes: 0
Unsuccessful attempts: 1
Discussions

Read evidence and context

Discussions that contain suggestions: 1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Suggestion · Original poster
I don�t think my driving habits have changed much, if any.
Original post Read captured discussion
Failing O2 sensor?

Frequently discussed actions (2)

These are separate views of the same evidence. Frequency alone does not establish a fix, and these counts must not be added together.

Replace much, if any

No successful repair reported for this finding.

0
Reported fixes: 0
Unsuccessful attempts: 1
Discussions

Read evidence and context

Discussions that contain suggestions: 1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Suggestion · Original poster
I don�t think my driving habits have changed much, if any.
Original post Read captured discussion
Failing O2 sensor?

Replace oxygen sensors

No successful repair reported for this finding.

0
Reported fixes: 0
Unsuccessful attempts: 1
Discussions

Read evidence and context

Discussions that performed work without a confirmed outcome: 1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Performed · outcome unconfirmed · Original poster
The O2 sensors were replaced about 2 years ago.
Original post Read captured discussion
Failing O2 sensor?

Coverage and how to read this overview

Counts describe captured discussions, not unique people or a diagnosis. Author identities are not reliably stored. Exact duplicate evidence is counted once across matching discussions; one discussion counts at most once per action/state. Multiple repairs reported together remain a combination. Suggestions and failed attempts do not establish a fix. Matches cover whole discussions and can include related faults, model variants and incomplete threads.

3 eligible posts · 0 unverified posts · 1 discussions match the subject in their title or opening post.

Rennlist: 1 discussions

0 evidence records excluded for query context · 0 excluded by outcome qualification · 0 adjusted by outcome qualification.

0 acknowledgements have no verified action link; they do not establish a repair result.

Generation: 20261026T222516Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources

POST 1 / ORIGINAL POSTEROriginal post

I feel like the gas mileage on my �99 has started to drop over the past few months. The car doesn�t smell gassy, the exhaust tips aren�t sooty, and the fuel dilution on the oil samples is below is currently less than 1. I don�t think my driving habits have changed much, if any. I took a screenshot with my Durametric and have attached that. The car was hot from a drive and at idle. I feel like the O2 sensor voltage ahead of the cat is reading high. The O2 sensors were replaced about 2 years ago. The car has a RoW DME flash so only the front O2 sensors are monitored (and only the bank 1 cam deviation is monitored because of the RoW). Is this voltage number of .35 indicative of an issue? The WSM reference says it is. I think my fuel trims seem to look ok.

POST 2Original post

Intake air leak, possibly?

POST 3 / ORIGINAL POSTEROriginal post

Quotes source post: 19707742

Definitely possible and I�ll smoke the engine again to see. I mainly wanted others to see my data to in case I was missing something else. What I don�t understand is how my fuel trims could be fine but the pre-cat O2 sensor voltage reads high?

This is a source reference. Confirm exact model applicability in the original material.